Water-meter compound reducing gear train



Dec. 1924- 1519563 I J. THOMSON *WATER METER COMPOUND REDUCING GEAR TRAIN Filed Feb. 23, 1923 2 Sheets-Sheet 1 INVENTOR.

J. THOMSON WATER METER COMPOUND REDUCING GEAR TRAIN Dec. 1 924. 1,519,563

Filed Feb. 23, 1925 2 Sheets-Sheet 2 INVENTOR.

Patented ee. 16, 1924,

UNITEQ STATES 1,51 ",fitld JOHN TI-IQMSON, 0F BROOKLYN, NEW YQRK.

WATER-METER COMPOUND REDUCING GEAR TRAIN.

Application filed February 23, 1923. Serial No. 620,694.

To all whom it may concern:

Be it known that 1, JOHN TnioMsoN, a citizen of the United States, and a resident of the borough of Brooklyn, city and State of New York, have invented a VVater-Meter Compound Reducing Gear Train, of which the following is a specification.

This invention relates to water meters, consisting in a compound reducing geartrain characterized by special adaptability for transferring high-speed motion, as from a positive displacing disc-piston or an inferential turbine, to the lower rate of motion required at the meter-register; and its dominant objects, relative to prior and prevailing practice, are to enhance the kinematic efficiency and reduce the operative resistance thereof.

The present applicant was the original designer of the compound type of spur geartrain for water meters; Which, although extensively used, was eventually discarded and has not since been employed.

The state of the art with respect to the foregoing was formerly well known, but a brief recitation thereof, based upon actual experience, is deemed pertinent to what will herein ensue. Thus, a central pinion meshed, right and left, with coordinating gears from which secondary pinions acted, right and left, with a central gear, and they might be so stacked-up interminably; but a so-called four-gear reduction was constructed, the pairing relation being t to 1 and the sum :1: :256. Two pairs of outer gears and pinions were freely mounted upon fixed spindles, separated by washers, and the central gear and pinion were mounted upon an inwardly projectingportion of the stufling-box spindle. The paramount objects of this system were expressed in a trade-catalogue of 1898 as follows: The driving strains to the central series are perfectly balanced, while those strains transmitted to the two outer series are but half that of the common (single series) train. The endurance, at high rates of delivery, was phenomenally good; but the. sensibility, for low rate registration, was about on a parity with that of the usual singleseries train having an equal reducing ratio. The reason for its sluggish sensibility was not then ascertained; but it has recently been discovered and new forms the dominating basis of this application.

In the drawings, which form a part of this specification,

Figure 1 is a nearly complete elevation of the improved compound gear train, in a form to be suspended in a water meter casing, a portion of which is indicated in dotted outline;

Figure 2 is an elevation of the train when revolved 90 from that of Figure 1;

Figure 3 is a bottom plan view, directly projected from Figure 1.;

Figure 4 is a top plan view, from Figure 2;

Figure 5 is a diagram illustrating the oldtime disposal of all the pinions and gears, previously alluded to;

Figure 6 is a diagrammatic plan-view, to an enlarged scale, of a central pinion and a pair of right and left gears, according to the present improvement;

Figure 7 is also a diagrammatic plan-view of a central gear and a pair of right and left pinions, which denotes the present im provement by an alternative mode of effecting the same kinematic result as is illustrated in Figure 6;

Figure 8 is a partial, detached section to better illustrate details more obscurely denoted in the elevations and in Figure 3', and

Figure 9 is a detached detail view denoting a modification in the spindle-mounting of the outer gears and pinions.

Three dominating improved features are to be dealt with; firstly, the meshing of the gears and pinions; secondly, the disposal of the co-ordinating pairs of the outer gears and pinions; and, thirdly, the mounting of the lower central gear and its pinion.

Referring to the elevations and plans, the primary driving pinion 9 meshes right and left with lower gears 10, 11, whose pinions 12, 13 mesh with the intermediate central gear 1 1, its pinion 15 meshing right and left with upper gears 16, 17, their pinions 18, 19 meshing right and left with the upper central gear 20, to which is attached the stuffing-box spindle 21, all being mounted between plates 22, 28 secured together by pillars, as 24, which are omitted in the elevations but denoted in Figures 3 4 and 8.

In earlier practice, to be explicit, 32-

revolved pitch gearing was used; the pinions having eight leaves and the gears thirty-two teeth; pairing relation, 4 to 1; ultimate relation 256 to 1. It was then supposed, or taken for granted, that not only must the relation be an even multiple, each pinion to its gear; but that each pinion and each gear must have an even number of leaves and teeth; also that any three co-ordinating elements, as a pinion and a pair of gears, or a gear and a pair of pinions, must necessarily lie in a right line, as in Figure 5. This concept of the problem resulted in a compound pinion-drive of no greater efficiency in the constancy of its curvilinear transmission of motion, as along the pitch lines, than if the drive were from one side only; and, as any pinion of less than twelve leaves is usually kinematically inefticient-especially so in a water meter because of the necessity for ample clearances-the train failed to subtend advantage in the important feature of sensibility. However, the mentioned suppositions were incorrect, as the solution here presented proves.

Thus, first'referring to Figure 6, by using a pinion of nine leaves, meshing right and left with gears each having'thirty-six teeth, subtending the former pairing relation of 4 to 1, and all being on a right line, as b the following benign condition is obtained, namelyz'A leaf, as 25, of the pinion lies exactly in a space, as 26, of the left hand gear; and a tooth, as 27, of the right hand gear lies exactly in the co-ordinating space diametrically opposite from the aforesaid leaf, 25, of the pinion. As a consequence, the pinion being the driving member, as arrow-28, one of its several leaves will be approximately continuously in its most effective transmitting position either in one gear or the other. In fact, the transfer of motion by this nine-leaved pinion along the pitch circles of the gears is, to say the least of it, fully equal to that of a pinion of eighteen leaves if the latter were also disposed along a right-line. And the same desirable result ensues when the gear is in the center, the compound impelling pinions being at the right and left of it.

The foregoing advantage can also be attained by using number of teeth. Thus, as see Figure 7, wherein the same pitch is employed as in Figure 6, the pinions have eight leaves and the gears thirty-two teeth, subtending a 4 to 1 relation as before; but by swinging one or the other of the pinions off from the right line 0, 0 to the angle d, equal to half of a pitch-space, which is here 5, 49, 30 in a gear of 32 teeth, the best possible operative condition is then obtained, that is when eight-leaved pinions are employed. However, the odd-leaved pinions and the rightline disposal of Figure 6 are preferable, For

pinions having an even example, where the utmost compactness is desirable, a seven-leaved pinion and a twentyeighth tooth gear, relation l to 1, would thus be more efficient than the former 8 to 32 combination on a right-line setting. I

In assembling a gear and pinion, it is important that the teeth and leaves shall synchronize or line-up. This 15 easily realized. Thus, as see F inure 6, the angular spacing of each pinion-pitch is 40, whilst that of four teeth in the gear also equals 40; but in Figure 7 it becomes 45. To obtain exact uniformity in either of these assemblages, it is merely necessary to press the parts together by means of a jig, or gauge, which is adapted to prevent other than the desired alignment, as of a pinionleaf withevery fourth tooth of a gear, or a pinion-space radiating to every fourth gear-space.

Then, as formerly, both pairs of outer gears and pinions were mounted upon one pair of spindles, disposed along a single right-line, as e, 6 Figure 5, the bearing surface areas were relatively limited; and a slight amount of wear thereat would permit a detrimental tilting action. This defeet, although nominal is not a negligible one, and may be effectively obviated by pressing the spindles, as 29, tightly into the pinions and causing their pivotal ends to revolve in plate-bearings; which is made possible by disposing each pair of outer gears at a right-angle to that of the other of them. For example, the lower pair of gears, as 111 100 Figure 1, lie along the right-line 71, h F igure 3, whilst the upper pair of gears, as in 7 Figure 2, lie along the right-line 2,71 at 90 to the line h, that is if the gearing is as shown in Figure 6. 9n the other hand, if" 105 the gearing is as shown in Figure 7, then one or the other of each pair would be swung off to an angle corresponding, as a minimum, to half of the space of one gearpitch. Or, as may be preferred, each outer 110 gear and its attached pinion may be mounted as shown in Figure 9. Here the upper portion of the bore is plugged, as 33, or it may be drilled blind, forming a supporting cap for the rounded end of the spindle 115 34, which is fixed in the lower plate 23. This, in fact, is the same system of bearing as was adopted in the earlier recited practice, except that its surface-area is about doubled; and that the weight of the gear is supported upon an end-pivot instead of a shoulder or washer. 1

Again, in former practice, the lower center gear and its pinion were journaled on an ex tension of the stuffing-box spindle, whereby it was possible, and in fact such occurrences were all too frequent, to push down the spindle, as when applying a change-gear to its upper outer end, thereby causing it to impinge. upon the underlying primary driv- Cir ing pinion. This fault is here corrected by mounting the lower central gear and its pinion upon a spindle 30, Figure 8, secured in a bridge-piece 31, attached to the lower plate, which may span or partially reach over the primary driving pinion. T his adds another feature of distinct advantage which that the upper end of this bridge-spindle may be rounded, whereby, if the stufiingbox spindle and its gear are shifted inwardly, they are stopped by this pivot and but little additional friction is thereby caused.

It may be pointed out that the off-set po sition from a right-line, as (Z in Figure 7, is the minimum and most effective disposal; but such is not the limiting angle, as it can be swung either wa and to various greater angles according to the pitch-spaces of the co-ordinating gear and pinion.

What I claim is:

1. In water meters, a compound reducing gear train comprising a central driving pinion, a pair or" laterally disposed gears meshing therewith, pinions rigid with said gears, a fixed bridge extending over said driving pinion, a central gear and its pinion journaled on said bridge, said central gear meshing with said pinions, a pair of laterally disposed gears meshing with the pinion of said central gear, pinions rigid with said last mentioned pair of gears, a stuffing box spindle and a gear rigid therewith meshing with said last mentioned pinions.

2. In water meters, a compound reducing gear train comprising a central driving pinion, a pair of laterally disposed gears meshing therewith, pinions rigid with said gears, a fixed member extending over said driving pinion, a spindle fixed in said member coaxially with said driving pinion, a central gear and its pinion rotatable on said spindle, said central gear meshing with said pinions, a pair of gears meshinn with the pinion of said central gear and disposed approximately at right angles to said first mentioned pair of gears, pinions rigid with said last mentioned nair of gears, and a central driven gear meshing with said last mentioned pinions.

3. In water meters, a compound reducing gear train comprising a driving pinion, astuliing box spindle coaxial therewith and spaced therefrom, a driven gear rigid with said spindle, coordinating gears and pinions transmitting motion from said driving pinion to said driven gear, a fixed member extending over said driving pinion, a spindle fixed in said member coaxial with said driving pinion and stufing box spindle and adapted to prevent said stuffing box spindle from bein shifted inwardly, said coordinatmg gears and pinions including a central. gear and its pinion mounted on said spindle.

l. In water meters, a compound reducing gear train comprlsing a driving pinion, a stufling box spindle coaxial therewith and spaced thereabove, a driven gear rigid with said spindle, coordinating gears and pinions transmitting motion from the driving pinion to the driven gear, adetachable bridge spanning said driving pinion, said coordinating gears and pinions including a central gear and its pinion journaled on said bridge.

5. In water meters, a compound reducing gear train comprising a driving pinion, a stuffing box spindle and a gear rigid therewith arranged coaxially with said driving pinion and central and laterally disposed gears and pinions transmitting motion from the driving pinion to the driven gear, the pinions and gears of said train having an even number of leaves and teeth respectively and said gears and pinions being so disposed that when a leaf of a central pinion occupies a gear-tooth space on one side a gear tooth will occupy-a pinion-leaf space on the other side, and when a tooth of a central gear occupies a pinion-leaf space on one side, a pinion leaf on the other side will occupy a gear-tooth space.

6. In a reducing gear train for water meters, a central gear and a pair of pinions meshing therewith on opposite sides, the pinion having an even number of leaves and the gear an even number of teeth, and the axis of one of the pinions being offset from the .right line joining the axes of the other pinion and gear, so that when aleaf of one pinion occupies a gear-tooth space, aspace of the other pinion is occupied by a gear tooth.

7. In a reducing gear train for water meters, a central pinion and a pair of gears on opposite sides thereof, the pinion having an even number of leaves and the gears having an even number of teeth, and the axis of one of the gears being ofiset from the right line joining the axes of the pinion and other gear, so that when a leaf of the pinion occupies a gear-tooth space of one gear, a tooth of the other gear occupies a pinion-leaf space.

This specification signed on this the 20th day of February, A. D., 1923.

JOHN THOMSON. 

